Make gralloc0 pass-through mapper handle layers

Gralloc0 does not support layers. This change is needed for Cuttlefish
to pass the GraphicsMapperHidlTest.ValidateBufferSizeBadValue VTS test

Bug: b/132087346
Test: vts-tradefed run commandAndExit vts -m VtsHalGraphicsMapperV2_1Target
Change-Id: I2ed7dae209629d401ccaf2fc0fd992d766b0fa9b
diff --git a/graphics/mapper/2.1/utils/passthrough/include/mapper-passthrough/2.1/Gralloc0Hal.h b/graphics/mapper/2.1/utils/passthrough/include/mapper-passthrough/2.1/Gralloc0Hal.h
index 18fbb6d..8540068 100644
--- a/graphics/mapper/2.1/utils/passthrough/include/mapper-passthrough/2.1/Gralloc0Hal.h
+++ b/graphics/mapper/2.1/utils/passthrough/include/mapper-passthrough/2.1/Gralloc0Hal.h
@@ -37,6 +37,10 @@
      Error validateBufferSize(const native_handle_t* bufferHandle,
                               const IMapper::BufferDescriptorInfo& descriptorInfo,
                               uint32_t stride) override {
+         if (descriptorInfo.layerCount != 1) {
+             return Error::BAD_VALUE;
+         }
+
          if (!mModule->validateBufferSize) {
              return Error::NONE;
          }